Birthday Cake Costco: How to Order, Size Guide, and What to Expect

When you need a birthday cake Costco can deliver, you’re not just buying dessert—you’re getting a reliable, no-fuss solution for big gatherings. Whether it’s for a kid’s party, a milestone birthday, or a last-minute celebration, Costco’s cakes are designed for crowds, not just taste. This isn’t some fancy bakery creation with piped roses and edible glitter. It’s a solid, well-made cake that feeds 12 to 40 people without breaking the bank. And yes, you can customize it—with a name, a message, and even a theme—though don’t expect intricate designs. What you get is consistency, value, and enough cake to keep everyone happy.

Ordering a Costco cake order, a pre-paid, in-store pickup cake available at most U.S. and UK Costco locations is simple, but timing matters. You need to call your local warehouse at least 24 hours ahead, and during holidays, book a week in advance. The most common size is the 9-inch round, which serves about 16 people—perfect for a family gathering. If you’ve got 30 to 40 guests, go for the 12-inch round or the sheet cake. Prices stay low, usually under $20, which is why so many people skip the local baker and head to Costco. The cake itself? Usually chocolate or vanilla, with a thick, sweet buttercream frosting. It’s not artisanal, but it’s dependable.

Don’t forget the cake size for parties, the standard measurement used to determine how much cake you need per guest. A 9-inch cake gives you about 16 slices, while a 12-inch can hit 24 to 30. For 40 people, you’ll want two 9-inch cakes or one full sheet. Costco doesn’t do tiered cakes or fondant, so if you’re looking for a showstopper, you’ll need to go elsewhere. But if you just need enough cake to last the party, with minimal stress, Costco nails it. You’ll also want to know about pickup times—most locations let you pick up during regular store hours, but you’ll need your order number and a valid ID. No delivery, no surprises, just walk in, grab your cake, and go.

What you won’t find at Costco? Gluten-free options, vegan cakes, or elaborate decorations. But you will find cakes that are made fresh daily, stored properly, and priced to move. That’s why they’re so popular. If you’ve ever been stuck planning a party with no time or budget, a birthday cake Costco is the quiet hero you didn’t know you needed. Below, you’ll find real guides on how to order one, what sizes work best, how to avoid common mistakes, and what to expect when you walk into the bakery counter. No fluff. Just what works.